Advanced multivariate approaches for selecting Moroccan drought-tolerant barley (Hordeum vulgare L.) cultivars

Abstract

Screening barley cultivars for drought tolerance is essential to increase crop production. The objective of the study was to assess the capacity of Moroccan barley cultivars to maintain grain yield production under drought conditions and to identify suitable drought tolerance indices for selection purposes. Nine barley cultivars were investigated under control (90% FC) and stress (40%) conditions under two irrigation regimes. Grain yield, agro-morphological traits, and ten drought screening indices were used to assess drought tolerance. Analysis of variances showed a significant effect of drought stress on various agro-morphological traits, with significant variability between cultivars. In normal conditions (Yp), a significant positive correlation was recorded between grain yield and geometric mean productivity (GMP), stress tolerance index (STI), mean productivity (MP), and harmonic mean productivity (HMP) indices. Principle component analysis and heatmap showed that ‘Firdaws’ and ‘Taffa’ are the highest yield producers in normal conditions, with high values of these indices. Regarding drought stress conditions, grain yield was positively correlated with yield index (YI), yield stress (YSI), and golden mean (GM). The highest values of these indices were recorded in the ‘Massine’ cultivar, showing it as the higher drought-tolerant. Consequently, the indices STI, MP, HMP, and GMP exhibited high positive correlations with grain yield in both irrigation regimes. Thus, they can be adopted as suitable indices in the selective breeding programs for Moroccan barley cultivars.